Might be a horrible idea but does anyone do themed classes for the holidays?

Trying to build a bit of engagement in my kids classes (ages 5 to 12) so thinking of doing a Halloween themed one and then a Christmas themed one.

Still want it to be proper Taekwondo but maybe throw in a bit of a twist when it comes to exercises and warms ups. What can I do for Halloween?

Normally class is generally structured as follows:

Warm up (agility game or exercises)
Basics
Forms
Padwork or some partner work
Fitness based game to finish (relay races, circuit or similar)

For my warm ups I quite often get them to go up and down the room like animals (bear crawls, crab walk etc) or the same but give it superhero names (The Flash = sprinting, Hulk = lunges + smashing hands together). Suggestions for Halloween versions?

Any ideas to adapt the rest of my class?_________________"Everything has its beauty, but not everyone sees it." ~ Confucius